Monday, April 12, 2010

I have never been a believer that power cords can magically improve a audio component or audio system’s sound. At the recent CES, a power cord manufacturer marketing guy told me that his cord could make an 80 percent improvement in image depth and width with any component you plugged the cord into. Hmm!

However, I do believe that a reasonably priced upgraded power cord can be an integral part of an audio system. Sound design principles, high-quality parts and build can produce a power cord that is more robust than the cheap stock cords that most components are shipped with. And, as important, a quality cord can be a barrier to potential noise and aberrant AC effects that can cause a loss of audio resolution in or in hi-fi, home theater or musician systems.

I have used accessory power cords for years in my system — as upgrades over those cheap cords that come with the products. The standard cables come in varying qualities and lengths (usually too short). I have seen cheap AC cables break off at the connector; I have had ground lugs wiggle free after repeated plug/unplug sessions, and I have had AC cords that picked up or leaked AC noise to my preamp/component cables. To ward off those potential maladies, I currently have a handful of various Kimber cords and a Monster Cable AC cable in my hi-fi system.

An upgraded accessory power cord can be a worthy investment to any audio system. A well-built one like the ESP MusicCord-PRO ES, can improve sound quality by eliminating the potential resolution-robbing AC line noise and maintaining optimum current for AC intensive products, such as amplifiers.

A few years ago, I discovered a line of USA-manufactured power cables from a small Michigan-based company: Essential Sound Products, Inc. (ESP). President Michael Griffin, an former GM design engineer, produces upgraded power cords for various audio applications. Griffin recommended the MusicCord-PRO ES 2-meter cord as a power cable that works well in hi-fi, home theater and music/music recording systems.

Features

The UL-approved, ESP MusicCord-PRO ES is a well-made, great-looking cord that sells for a street price of $249. Not bad in this world of thousand dollar plus power cords. According to ESP’s Griffin, the key to his power cord’s performance is multiple small conductors used in “parallel.” The engineering intent, according to Griffin, combine the high current capacity of a large gauge cable and phase eliminating properties of small gauge cable.

According to ESP, “large gauge conductors have lower resistance but higher internal inductance.” The theory surmises that larger conductors “have longer time constants, meaning current changes slowly.” The company states: “Smaller conductors have less internal inductance and a faster time constant, but don’t have the current capacity.” Thus, the multi small-conductor arrangement offers, a fast-time constant and high current capacity,” ESP claims.

I don’t know if the “multiple small conductors in a parallel design” actually improves audio quality over any other design, but I appreciated Mr. Griffin’s attention to his products’ design/construction quality. He pointed out that a power cord can ward off potential AC noise that can be detrimental to your audio; and, as I discovered, the ProES cable did reduce noise in my system.

The details

MusicCord-PRO ES multi-conductor cable is 14-AWG equivalent. The cord is also cryogenically frozen to –300 F, which is said to irreversibly align grain boundaries increasing conductivity and reducing grain and hash distortions. The cord sports an oversized 12 gauge ground conductor and 95 percent coverage, braided copper shield, designed to reduce RFI that can contaminate AC power. It also can prevent residual hum and buzz that can be caused by a power cord’s strong magnetic field when closely routed next to signal cables.

Other features include a NEMA 5-15P custom-molded, hospital-grade (UL-498) plug with solid, special-treated brass pins and custom termination. The cable also utilizes a custom-molded IEC connector and reinforced cable-to-connector interface with integral strain relief to give it a long life. For $250 bucks an AC cable should have a long, long life.

A well-designed power cord should maintain the audio transparency — as much as possible. That is why I liked the ESP MusicCord-PRO ES’s design features; I figured it could provide a barrier to noise-infused AC power. And by preventing noise contamination, the audio stays transparent.

The cables can be ordered with optional C-13 (90-degree LH & RH angled plugs). Current rating, approved to UL-817 requirements, is 15-amps continuous. The cable also is available with C-19 connector and variable lengths (upcharge) that range from .5 meters to 3 meters.

The stiff cable housing is covered with a woven polyester sleeving. It is not easy to bend when trying to route in curved paths, but you know it will be durable. (To illustrate that durability, I accidentally dropped a boxed 40-pound component on my Pass amp — right where the MusicCord-PRO ES was plugged in. After the box made a bouncing hit on top of the AC’s cable plug at the amp, I thought for sure the dropped box had broken the cable plug. Neither the cord or plug suffered damage, but the plastic IEC ring in the Pass was broken in two pieces).

I think that a well-designed power cord should maintain the audio transparency — as much as possible. That is why I liked the ESP MusicCord-PRO ES’s design features; I figured it could provide a barrier to noise-infused AC power. And by preventing noise contamination, the audio stays transparent.

The home theater system featured a Pioneer Blu-ray player, Onkyo Pre-Pro and two Carver amps. The amp cords were not detachable. The musician rig included a Fender solid-state Deluxe 90 guitar amp and a variety of guitars.

Where I heard the biggest improvement with the ESP cords was in my hi-fi system and recording rig. Most of the improvement was AC line noise reduction over the stock cords. But my set up is not that simple, and I had to do more than switch out power cords to hear the difference. Let me explain.

The audition

To check for any audible changes, I had to ascertain what the hi-fi and recording system sounded like with the stock AC cords. To remove other variables, though, I first disconnected my balanced power units, which have their own transformers. I added the balanced power units about 10 years ago because my basement refrigerator, on the same circuit as my hi-fi and recording setup, produced an annoying AC buzz through the speakers. The cycling of the gas/electric furnace also caused some intermittent switching noise. To this day, the noises persist — with or without the balanced powered boxes.

When I turned up the headphone amp to maximum with the Oppo as the source — and no music playing — just to hear what is going on in the noise floor, I heard a little additional secondary AC hash through the phones. That noise was not as loud with the MusicCord-PRO ES.

The balanced power approach has done a good job reducing the fridge and furnace noise, but each unit’s internal isolation transformer exhibits considerable low-level mechanical hum/vibration that can be heard during low-level hi-fi and recording rig speaker playback. It is annoying. During this test, I thought, “what if I could get rid of the line noise and mechanical transformer noise by just putting in better power cords.”

With the balanced power unit removed from the AC chain, I plugged in the standard cords into the amp, preamp and high-res player (hi-fi). As expected, when the fridge kicked on, AC hash and buzz could be heard at low levels through the speakers. I also heard the switch noise of the furnace. Minus its balanced power unit, the same noise also was present in my recording rig. The DAC 1 Pre had plenty of AC buzz through the headphone amp.

With the ESP MusicCord PRO ES cords plugged straight into the wall outlet, however, the fridge line noise was reduced to the same level as when the standard cords were plugged into the balanced power unit. Maybe I don’t need the balanced power units after all. The startup switching noise from the furnace, however, did not go away, but its intermittence means it is only there when the furnace first cycles up.

I tried the Kimber cords using the same setups, but I still heard some refrigerator buzz. Also, when I turned up the headphone amp to maximum with the Oppo as the source — and no music playing — just to hear what is going on in the noise floor, I heard a little additional secondary AC hash through the phones. That noise was not nearly as audible with the MusicCord-PRO ES.

It may be that potential AC noise conducted by the AC cable is better contained in the ESP cable so that the unbalanced preamp and component cables don’t pick up the noise. Whichever the case, the MusicCord-PRO ES seemed cleaner. I also noticed that the deep bass seemed a tad tighter versus the stock cord when the amp, preamp and source were all connected to the AC via the ESP MusicCord-PRO ES’s.

More outlets, please

I also auditioned the 15-amp MusicCord- PRO Power Distributor ($499 street price), which is an six-outlet strip (Green Dot hospital grade) that has plenty of space between the outlets and is solidly constructed, with its non-resonant, internal RFI shielding and extruded aluminum chassis that is packed with internal damping material. It has no switches or reset breaker, but contains a replaceable 15 amp fuse. The Pro strip also has a surge-suppression rating of 340 joules. It is connected to the AC outlet via a non-detachable, 2-meter MusicCord-PRO power cord.

Though a bit larger than the cheap power strips from the hardware store, it is perfect for those uses where you don’t need sequential turn-on (audiophile rooms, musician rigs, recording rigs, or home theater setups, if you like to push the component buttons manually).

Like the power cord, the ESP MusicCord-PRO Power Distributor was clean and quiet and produced no mechanical noise — low level or otherwise — that impeded the full resolution of my audiophile or home theater setup. Unlike my balanced power unit, it emanated no hum or vibration; the strip is dead quiet.

The ESP MusicCord-PRO Power Distributor was clean and quiet and produced no mechanical noise — low level or otherwise — that impeded the full resolution of my audiophile or home theater setup. Unlike my balanced power unit, it emanated no hum or vibration; the strip is dead quiet.

The only negatives I found with the ESP products are the cords’ stiff, outer housing. The stiff, polyester-woven jacket required some muscle to bend it around objects in the quest for sensible routing. In my audiophile rig, I have a four-glass shelf rack with three large column supports. The wall receptacle is behind the rear column, I really had to manhandle the ESP MusicCord-PRO ES to get it to bend around the column.

The verdict

I believe that an upgraded accessory power cord can be a worthy investment to any audio system. A well-built one like the ESP MusicCord-PRO ES, can improve sound quality by eliminating the potential resolution-robbing AC line noise and maintaining optimum current for AC intensive products, such as amplifiers.

The other positive, which often gets overlooked, is the fact that that upgraded cords should be more durable than the included cords that come with audio components. If you are an audio buff like me, and you change components a lot, with frequent plug/unplug power cord cycles, these repeated power-cord maneuvers necessitate a more robust cable that can take the wear and tear. I can attest that the ESP are tough cables.

At $249, the ESP MusicCord-PRO ES cables are not too expensive in today’s world of exotic power cords. If you can live without croyogenically-frozen conductors and special termination process, little brother MusicCord -PRO is a bargain (at $149 street). The ESP MusicCord-PRO Power Distributor is more money, but if you need multiple outlets to hold your larger accessory cables, with ample noise resistance, it is a good buy. Both ESP products are highly recommended! and get the Stellar Sound designation.